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2002 Scientific Report

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also be controlled by

also be controlled by genetic engineering. These transgenic mice are excellent models for studying the expression and function of the transgene in the biological environment of the living mouse. Gene-targeting mutations are introduced into the mouse by genetic manipulation of pluripotent embryonic stem (ES) cells. ES cells, which are derived from 3.5-day-old embryos called blastocysts, have the potential to contribute to all tissues of a developing mouse. Genomic DNA containing the gene of interest is isolated, mutated, and inserted into ES cells. The mutated gene integrates into the genomes of the ES cells and, by a process called homologous recombination, replaces one of the two wild-type copies of the gene in the cells. These genetically modified cells, containing one mutant copy of the gene, are injected into wild-type blastocysts where they integrate into the developing embryo. These embryos, containing a mixture of wild-type and mutant ES cells, develop into offspring called chimeras. Offspring of chimeras that inherit the mutated gene are called heterozygotes, because they possess one copy of the mutated gene. The heterozygous mice are bred together, or intercrossed, to produce mice that completely lack the normal gene; these homozygous mice have two copies of the mutant gene and are called genetargeted or gene “knock-out” mice. A related technology, gene knock-in, employs similar methods to insert functional genes into specific locations in the mouse genome. Ultimately, gene-targeted mice can be observed for abnormalities associated with the inserted genetic change, and they provide powerful research tools for studying gene function in living organisms. The Germline Modification Laboratory is a full-service lab that functions at the level of service, research, and teaching. VARI and Michigan Life Science Corridor clients will be assisted in the design and implementation of transgenic and gene-targeting experiments and, if necessary, trained in these techniques. New stem cell lines can be derived, and spectral karyotypic (SKY) analysis of mouse chromosomes—using highquality, 24-color fluorescent in situ hybridization paints—can aid in the detection of subtle and complex chromosomal rearrangements in ES cells. Upon production of the genetically modified mice, our lab will assist in developing breeding schemes and provide for the complete analysis of the mutant mice. The vivarium utilizes two Topaz Technologies software products, Granite and Scion, for integrated management of the vivarium finances, the mouse breeding colony, and the Institutional Animal Care and Use Committee (IACUC) protocols and records. The efficiency of mutant mouse production and analysis is enhanced using the Autogen 9600, a robotic, high-throughput DNA purification machine. Imaging equipment, such as the PIXImus Mouse Densitometer and the Acuson Sequoia 512 ultrasound machine, is available for noninvasive imaging of mice. Mouse strains are archived using sperm cryopreservation and reconstituted using in vitro fertilization techniques. Additional services provided by the vivarium technical staff include an extensive xenograft model development and analysis service, rederivation, surgery, dissection, necropsy, breeding, and health-status monitoring. In summary, the goal of the germline modification laboratory is to develop, provide, and support high-quality mouse modeling technology services for the Van Andel Research Institute investigators, Michigan Life Science Corridor collaborators, and the greater research community. 41

External Collaborators Narayanan Parameswaran, Bill Smith, and Bill Spielman, Michigan State University, Lansing Douglas Ashley Monk, Michigan State University, Lansing Gary Litman, University of South Florida, Tampa Dan Rosen, Wadsworth Center, New York State Department of Health, Albany Publications Su, Ting, Qing-Yu Zhang, Jianhua Zhang, Pamela J. Swiatek, and Xinxin Ding. 2002. Expression of the rat CYP2A3 gene in transgenic mice. Drug Metabolism and Disposition 30(5): 548–552. From left to right: Swiatek, Van Dunk, Sisson, Davidson From left to right: Dylewski, Ruff, Eagleson, Martin, Boguslawski, Buckrey, Guikema, Van Noord, Ballard 42

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